UsesFolkloric- The Malays use a decoction of roots for fevers; the leaves for poulticing, and the bark as astringent for diseases of the tongue.
- Fruit decoction used for diarrhea and dysentery.
- Edible pulp (aril) is used as an refrigerant in fevers.
- In China, fruit is recommended for severe dysentery, and as a warm carminative in "cold" dyspepsia.
- In Malaya, astringent bark is used as remedy for thrush. Decoction of roots taken as febrifuge. source
OthersElsewhere, seed used to extract oil; also roasted and
eaten.

Studies• Antioxidant / Antibacterial:
Study yielded high amounts of phenolic compounds in the peel extracts, highest in the methanolic extract, exhibiting higher antioxidant activity than the seed extracts. All peel extracts exhibited antibacterial activity against five pathogenic bacteria. (1)
• Phytochemicals / Monoterpene Lactones: Study isolated two new diasteromeric monoterpene lactones 1
and 2. Both underwent antimicrobial testing. (2)
• Antioxidant in Rinds:
The normally discarded rind was found to have extremely high antioxidant
activity. The study of the extract revealed high phenolic content, low
pro-oxidant capacity and strong antioxidant activity with cosmetic,
nutraceutical and pharmaceutical potentials. (3)• Antiviral / Anti-Herpes:
Tested for anti HSV-1 virus activity, N lappaceum significantly affected
the development of skin lesions and reduced mortality. (4)
• Cancer Chemopreventive / Waste Product / Rind:
Study of NL extract showed an antiproliferative effect associated with apoptosis. The extract induced G2/M arrest of HOS indicating inhibition of cell cycle progression as one of the mechanisms. Extract was non-cytotoxic to normal cells at its inhibitory concentration. The study showed a potential for the rind, an underutilized waste product of Nephelium lappaceum.| (5)
• Antioxidant in Peels / Elliagitannins:
The methanolic extract of NL peels exhibited strong antioxidant properties. Study isolated ellagic acid, corilagin, and geraniin. The ellagitannins, principal components of rambutan peels present as potential for utilization in both food and medical industry. (6)
• Fatty Acid Synthase / Potential Cancer and Obesity Therapeutics:
Natural products inhibiting fatty acid synthase are potential therapeutic agents to treat cancer and obesity. Study isolated 10 compounds in NL, including flavonoids and oleane-type triterpene oligoglycosides. Compounds 8 and 9 were hederagenin derivatives. The isolates showed inhibitory activity against FAS. Results suggest the hulls of NL may be a potential source of promising FAS inhibitors. (7)
• Anthocyanins / Antioxidant:
Anthocyanins, known to possess high antioxidant activity, were extracted from rambutan pericarp tissue. However, the pericarp tissue is usually discarded as waste. Results suggest a potential for extraction of health-beneficial bioactive compounds such as anthocyanins, with potential benefit to the rambutan industry. (8)
• Seed and Seed Oil / Physiochemical and Nutritional Composition:
Seeds were found abundant in fats (38.(%), protein (12.4%), carbohydrate (48%). Seed oil yielded oleic acid (40.45%) and arachidic acid (36.36%) as major fatty acid. Results showed rambutan seed is a potential source of oil or carbohydrate for the human diet and for food product application. (9)
• Geraniin / Anti-Hyperglycemic: Study described rapid isolated of geraniin. In addition to high antioxidant activity and low pro-oxidant capability, geraniin showed in vitro hypoglycemic activity and aldol reductase inhibition activity, and was able to prevent the formation of advanced glycation end-products. Results support the used of a geraniin-standardized N. lappaceum extract for the management of hyperglycemia. (10)
• Seed Waste as Source of Fat: Study reported that the seed kernel of rambutan, a product generally considered waste material, can be used as a sustainable source of fats. Seed kernels yield a considerable amount of fat and high arachidic acid that makes the fat highly stable to oxidation, and a potential source of industry fats. (12) (13)
• Ellagitannins / Antioxidant: Study isolated ellagitanins (1) ellagic acid (2) corilagin and (3) geraniin. Geraniin was the major component, exhibiting much greater antioxidant activities than BHT in both lipid peroxidation and DPPH assay. Results suggest use of the isolated ellagitannins from the peels for both medicine and food industry.
• New Hederagenin Glycoside: A new oleane-type triterpene oligoglycoside, hederagenin 3-O-(3-O-acetyl-i-D-xylopyranosyl)-(13)-h- L-arabinopyranoside, together with four known compounds, was isolated from the hull of Nephelium lappaceum. (14)
• Fruit Rind Safety / Cosmetic and Pharmaceutical Potential: Studies have suggested the fruit rind can be considered an easily accessible source of natural antioxidants and antibacterial agent. Study of ethanol extract showed no toxicity in doses up to 5g/kg. Results suggest rambutan rind extract should be safe for use in cosmetic, nutraceutical and pharmaceutical applications. (16)
• Anti-Inflammatory / Rind / Collagen-Induced Arthritis: Study evaluated the protective efficacy of an ethanol extract of N. lappaceum rind against collagen-induced arthritis in rats. N. lappaceum rind extract showed significant and dose-dependent suppression of the physiological, biochemical and histopathological changes produced during collagen-induced arthritis in rats. N. lappaceum extract supplementation may be beneficial in preventing the tissue damage and inflammatory conditions in arthritis. (17)
• Thermal Properties of Monoglycerides / Natural Source of Saturated and Monosaturated Fatty Acids: Paper studied the transformations of reserve lipids of species of Nephelium lappaceum, exploring the transition from native triglycerides to pure monglycerides. Results suggest useful applications in food, cosmetics, and pharmaceutical industries. (18)
• Hepatoprotective / Rind: Study evaluated the protective effect of a rind extract on paracetamol-induced hepatotoxicities in mice. Results showed a hepatoprotective effect through improvement of GSH content. (19)
• Antibacterial / Rind: Study evaluated the antibacterial activity of rambutan rinds and minimum inhibitory concentrations (MIC) against pathogenic bacteria. Results showed crude extracts to have a broad spectrum of antibacterial activity , with greatest inhibitory activity against Staphylococcus aureus. (20)
• Antidiabetic / Seed Infusion: Study evaluated the effect of rambutan seed infusion on blood sugar levels and body weight of mice with alloxan-induced diabetes. Results showed significant reduction in blood glucose and body weight of mice. The effect was comparable to glibenclamide.(21)
• Antiproliferative / Breast, Cervical and Osteosarcoma Cancer Cell Lines: A methanolic yellow NLPE showed most potent cytotoxic activity against several tested cancerous cell line. The yellow NLPE may represent an experimental therapeutic approach for breast cancer treatment. (22)
• Biocoagulant / Seed / Turbidity Removal: Study evaluated the ability of coagulation performance of rambutan seed in comparison to alum for potential use in turbidity removal in water and wastewater treatment industry. 1 M NaCl was an effective solvent for extracting the active coagulant agent in rambutan seed, with about 99 % turbidity removal. Results suggest a potential for using rambutan biomass as biocoagulant. (23)
• Seed and Seed Oil Composition: Study showed rambutan (Nephelium lappaceum) seed is a potential source of oil or carbohydrate for the human diet and also for food product application. (See constituents above) (24)
• Anti-Nutrient Contents / Pulp, Seeds and Rind: Study for anti-nutrient content of pulp, seeds, and rind of N. lappaceum yielded saponin, alkaloid, hydrocyanic acid, phenols, oxalate, tannins, phytates. The anti-nutrient constituents were in small insignificant amounts in all parts of the fruit. Flavonoids, alkaloids, tannin, and phenol were significantly high in the rind while phytate and oxalate were significantly high in the seeds. (25)
• Antibacterial / Seeds: Study evaluated the antibacterial activity of aqueous seed extracts of Nephelium lappaceum and Litchi chinensis. Both extracts showed moderate inhibition against pathogenic bacteria viz. gram positive ( Staphylococcus aureus, S. pyogenes and Bacillus subtilis) and gram negative (E. coli, P. aeruginosa) bacteria. (26)
• Acute and Subchronic Toxicity Studies / Rind: Study evaluated the safety of rambutan rind extract in male Wistar rats. In acute toxicity study, the LD50 was found to be greater than 5000 mg/kg of RRE. In sub-chronic toxicity study, no mortality or sign of toxicity was found up to 1000 mg/kg/day of RRE. (27)
• Polyphenol Oxidase / Peel: Polyphenol oxidase is a common copper containing enzyme responsible for melanization in animals and browning in plants. Among the most effective inhibitor for the enzyme with 10mM catechol as substrate was ascorbic acid. (28)
• Seed and Seed Oil: Study analyzed the physiochemical and nutritional composition of seeds of Nephelium lappaceum. Results suggest rambutan seed has the potential as a source of oil or carbohydrate for the human diet and food application. (see constituents above) (29)
• Inhibitory Potential on Adipogenesis / Seeds: Study evaluated the phytochemical content and inhibitory potential of rambutan seeds extract and fractions on glucose-6-phosphate dehydrogenase (G6PDH), α-glucosidase, and triglyceride activities ex vivo in 3T3-L1 cell line (pre-adipocytes) for antidiabetic and antidiapogenesis agent screening. Results showed the seed extract and hexane fraction to possess inhibitory potential on G6PDH and α-glucosidase as well as TG level. (30)• Cocoa Butter Substitute / Seed Fat: Study is an overview of the compositional data of Nephelium lappaceum and rambutan seed fat for usage in chocolate product. Study suggests rambutan seed fat can be used as substitute in cocoa butter chocolate products. The extracted fat from the seed can be used for manufacturing candles, soaps, and fuels; also, as a possible source of natural edible fat. (32)